The research objective of this grant proposal involves several lines of related research. These are: 1) The development of more effective methods to isolate and characterize complicated and fragile substances of biological interest such as biopolymers. This objective is illustrated by the past development of countercurrent distribution and thin film dialysis and their application to selected problems. The dialysis is of particular interest to the hemodialysis program. 2) The study of the interaction of biopolymers with themselves and with various solvent components. This line involves studies of association, binding, conformation, steric effects, etc. It is closely related to the first line since truly delicate and selective separations can be accomplished more certainly by a better understanding of such interactions. Beyond this objective, such studies will add to the growing body of information regarding the way biochemicals are organized in tissues and thereby serve their purpose. 3) The actual isolation and structural determination, if unknown, of substances shown to be present in tissues by virtue of some biological activity. This will include determination of co-valent structure, their conformation in solution and their conformational mobility.